A spokeswoman for The Colosseum at Caesars Palace tells ET that Elton developed a serious respiratory infection last Sunday and the condition worsened, requiring him to be hospitalized Wednesday at Cedars-Sinai Medical Center in Los Angeles.

After extensive tests at the hospital, doctors recommended that the pop star suspend performances for at least the next seven days to focus on getting adequate rest while he is treated with antibiotics.

Speaking about the cancellations, Elton said in a statement: "It feels strange not to be able to perform these 'Million Dollar Piano' concerts at The Colosseum. I love performing this show and I will be thrilled when we return to The Colosseum in October to complete the eleven concerts soon to be scheduled. All I can say to the fans is sorry I can't be with you. I hope to see you soon at this wonderful theatre at Caesars Palace."